The use or desirability of using titanium electrodes in electrolytic processes for the extraction of metals and metal oxides is well known. See, for example, U.S. Pat. Nos. 4,319,977 and 4,460,450. This use or desirability of using electrodes constructed of titanium is based on a number of advantages offered by titanium over other materials that have been employed in such electrode structures in the past. Of the numerous advantages provided by the use of titanium electrodes, the most noteworthy are their durability, low corrosiveness and the improved quality of the metal or metal oxide deposits recovered therefrom on a long-term basis.
However, according to U.S. Pat. No. 4,319,977, a major drawback to the use of such titanium electrodes is their cost, titanium being an expensive metal. Thus, in the above patent, it is disclosed that much effort has been expended in developing electrodes, based on titanium, of reduced cost but without sacrificing the advantages associated with the use of titanium. One such development disclosed in the above patent comprises an electrode of a sandwich-type construction in which a core metal having good electrical conductivity is coated with titanium on both sides. Such sandwich-type construction reduces the cost of the electrode while retaining all of the advantages afforded by titanium.
Another development disclosed in the above patent comprises an electrode utilizing corrugated sheets of titanium. According to the above patent, the conventional thickness of titanium electrodes is on the order of about 4 mm. The use of corrugated sheets of titanium as electrodes presumably allows the use of thinner sheets of the titanium metal thereby reducing the overall costs of the electrode while retaining the rigidity associated with titanium electrodes constructed of thicker sheets of the metal. However, the reduction in thickness afforded by corrugating sheets is said to be very small and hardly pays for the cost of corrugation. The disclosure in U.S. Pat. No. 4,319,977 concludes that, overall, simple (i.e., single) corrugated sheets of titanium have not proven to be economically viable and particularly in the thicknesses desired.
The invention in the above referenced patent itself is directed to an improved electrode for use in the electrolytic production of manganese dioxide. the electrode disclosed in the referenced patent comprises two continuous sheets of a metal, e.g., titanium, joined in a face-to-face relationship. At least one of said sheets is corrugated so as to provide rigidity to the electrode. In turn, the two joined sheets are attached to a hanger bar by means of a series of straps machined into the sheets.
Another patent disclosing the use of corrugated sheets of metals such as titanium in electrode assemblies is U.S. Pat. No. 4,460,450. In general, the disclosure in this patent relates to the providing of an electrode having current-carrying components which provide good electrically conductive connections between a core metal and the jacket metal of said current-carrying components.